| 摘要 |
PURPOSE:To obtain a method for the production by which it is possible to control the shape, grain-size, moreover the crystalline structure of a particle without using expensive reacting agents of at a low cost, by providing a process in which ternary carbonate powder is stored by means of bulk density and packed density. CONSTITUTION:In a method for the production of ternary electron emission substance by the precipitation method of nitriates of barium, strontium and calcium; said method consists of two processes, that is, the first process is one which coprecipitates ternary carbonates by reacting said ternary nitrates with carbon dioxide, and the second process is one which selects said ternary carbontes powder preduced by the above first process due to the bulk density and the packed density. It has come clear that the decision of the shape and diameter of the particle is possible due to the values of bulk density and the packed density, and that the preferred bulk density is from 0.72-0.89g/cm<3> and the preferred packed density is from 0.91-1.10g/cm<3>. By this method, the shape and the grain-size of the particle made of electron emission substance obtained by coprecipitation can be very accurately sorted due to the values of the bulk density and the packed density. |
